When Max first leaves the refinery, they give him six cans of fuel which he carries on a wooden pole, three on one side, three on the other. To begin with, if these tanks were full, they would weight around 80lbs each, making the total weight nearly 500lbs., not too much to carry for a stout dude but probably too much for a wooden pole. But, when he reaches the gyro captain he drops the cans and they move, and more importantly sound, like they are quite empty.